This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-346461, Dec. 6, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a rough/fine movement drive mechanism of a focusing device, wherein rough/fine movement handles are operated for vertical rough/fine movement of a table, thereby effecting focusing, for example, on a sample of a microscope.
FIG. 1A and FIG. 1B schematically show a microscope described in Jpn. Pat. Appln. KOKAI Publication No. 10-26730. FIG. 1A is a plan view, and FIG. 1B is a left-side view. A revolver 2 is rotatably disposed at an upper part of a microscope body 1. An objective lens 3 is attached to the revolver 2. A lens-barrel 4 and an eyepiece 5 are provided on an optical axis of the objective lens 3.
A stage receiver 6 is vertically movably disposed at the microscope body 1. A stage 8 for mounting of a sample 7 is provided on the stage receiver 6. A left-side focusing handle 9, a right-side focusing handle 10 and a stage handle 11 are disposed at a lower part of the microscope body 1. The left-side focusing handle 9 is buried in the microscope body 1. If the left-side focusing handle 9 is projected like the right-side focusing handle 10, it would interfere with the stage handle 11.
With the microscope having this structure, the right-side focusing handle 10 or left-side focusing handle 9 is rotated to vertically move the stage receiver 6 and stage 8, thereby effecting focusing on the sample 7.
Since the left-side focusing handle 9 is buried in the microscope body 1, the focusing handle 10 and stage handle 11 are disposed symmetrical in the right-and-left direction. This enhances operability. In fact, since the frequency of use of the left-side focusing handle 9 is low, the right-hand focusing handle 10 alone is used in most cases.
FIG. 2 shows the structure of a focusing device of a microscope described in Jpn. Pat. Appln. KOKAI Publication No. 3-111805. A stationary cylinder 23 is fixed in a through-hole portion in the microscope body 20 by means of fixing screws 21, 22. A transmission shaft 24, a rough-movement coupling shaft 25 and a fine-movement coupling shaft 26 are rotatably engaged in succession within a hollow part of the stationary cylinder 23. Rough-movement rings 27 are disposed at both ends of the rough-movement coupling shaft 25. Rough-movement handles 28 are screwed on the rough-movement rings 27. Fine-movement rings 29 are disposed at both ends of the fine-movement coupling shaft 26. Fine-movement handles 30 are screwed on the fine-movement rings 29.
FIG. 3 shows a state in which the left-side rough-movement handle 28 and fine-movement handle 30, for example, are removed in the focusing device, and a cover 31 is attached to conceal the place of the removed elements. Similarly, the right-side rough-movement handle 28 and fine-movement handle 30 may be removed and a cover may be attached for concealment.
Although not shown, the rough-movement handle 28 and fine-movement handle 30 are disposed near the handle for the stage for mounting of the sample. If the operabilities of those handles are to be maintained, the handles need to be disposed very close to each other. As a result, the handles become difficult to operate.
The stage handle is disposed in the vertical direction with respect to the rough-movement handle 28 and fine-movement handle 30. Normally, it is disposed on one of the right and left sides.
As regards the microscope shown in FIG. 1, the stage handle 11 is disposed on the left side. In some cases, however, the stage handle 11 needs to be disposed on the right side from the standpoint of the operability for observation by the user.
In the case where the stage handle 11 is disposed on the right side, the microscope body 1 and focusing handle 10 cannot be shared with the case where the stage handle 11 is disposed on the left side. Moreover, the position of the stage handle 11 cannot be changed to the left side or right side, according to the user""s preference.
The manufacturer is required to make two sets of the same microscope bodies 1 and focusing handles 10 for the left-side and right-side positioning of the stage handle 11. This makes the structure and manufacture complex.
On the other hand, the user is required to choose, from the beginning, a microscope provided with the left-side or right-side stage handle 11. To change the position of the stage handle 11 to the left side or to the right side after the purchase of the microscope requires considerable labor.
On the other hand, in the focusing device shown in FIGS. 2 and 3, when the rough-movement handle 28 and fine-movement handle 30 are to be attached/detached, bonding, for example, needs to be broken. The user is unable to perform modifications for detaching/attaching the rough-movement handle 28 and fine-movement handle 30. If both the right-side and left-side rough-movement handles 28 and fine-movement handles 30 are removed, the operation of the device is disabled.
The object of the present invention is to provide a drive mechanism for a focusing apparatus, wherein a fine-movement handle can be attached/detached by a user with a simple work, while a space necessary for the operations of a stage and a space around the fine-movement handle can be provided.
In order to achieve the object, according to a first invention, there is provided a rough/fine-movement drive mechanism of a focusing device, comprising: a rough-movement coupling shaft, to both ends of which rough-movement handles are attached; a fine-movement coupling shaft rotatably provided coaxially with the rough-movement coupling shaft; a movement mechanism for vertically moving a stage in accordance with rotation of the rough-movement coupling shaft, and decelerating rotation of the fine-movement coupling shaft and moving the stage by an amount of movement less than an amount of movement provided by the rotation of the rough-movement coupling shaft; a fine-movement ring provided at each of both ends of the fine-movement coupling shaft, disposed outside each of the rough-movement handles, and having a smaller outside diameter than an outside diameter of each of the rough-movement handles; and a fine-movement handle detachably attached to at least one of the fine-movement rings.
According to a second invention, in the rough/fine-movement drive mechanism of a focusing device according to the first invention, the fine-movement handle has a cylindrical shape elongated in an axial direction of the fine-movement coupling shaft.
According to a third invention, in the rough/fine-movement drive mechanism of a focusing device according to the first invention, indices are put on a surface of the fine-movement ring, and lines indicating the indices are put on a circumferential portion of the fine-movement handle.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.